Rotary brushes now commonly on the market and in use consist of a drum which carries bristle strips on its periphery. The strips are mounted in various ways on the drum and are usually removable so that they can be replaced after wear. It is important that the strip be of such a nature that it can be produced with simple tooling and at a low cost of time and material.
At present a popular brush strip is produced by a slow, costly method of providing a metal strip with holes punched at longitudinally spaced intervals which are to receive the bristles. The closed ends of U-shaped bristles are bunched together and then inserted in these holes; the number of ends must be accurate so that the holes will be filled. The bristles are plastic and are retained in the holes by a heat process. This method of producing bristle strips is limited to plastic bristles and is difficult to perform and time-consuming. It also produces a weak strip that is difficult to handle, the weakness resulting from the successive holes. Due to this weakness, the strip tends to bend at longitudinal intervals from its plane and thus makes it difficult to handle in inserting it into the end of the receiving grooved track or channel on the drum. This track usually has opposed laterally spaced guide grooves for receiving laterally-extending flanges on the bristle strip.
Another method forms a strip for sliding into a track on the drum by double-joining back-forming, etc. to provide an outwardly-opening, bristle-receiving channel with laterally-extending lower flanges adapted to slip in the laterally-extending grooves of the drum-mounted tracks. This method requires expensive tooling and produces a weak arrangement that results in a leverage problem during rotation of the drum tending to spring apart the flanges of the outwardly-opening bristle-receiving channel and thereby release the bristles.
Many other forms of tracks are provided on drums in the prior art to receive bristle carrying strips. This invention provides a strip which can slip in any guide track that provides laterally-opposed receiving guide grooves which extend longitudinally of the track.
The present invention provides a strip brush for mounting on a rotary drum which is of simple construction and can be removably slipped readily into tracks of the type now usually provided on rotary drums. This bristle strip can be produced without high-cost materials, and expensive tooling and time-consuming operations resulting in a low cost strip. It can be inserted readily in the drum track, will be effectively retained therein and can be removed with ease when it is necessary to replace it. The bristle strip is stronger and easier to install and remove as compared to prior art strips and as indicated above is less costly to produce.